1. Field of the Invention
The present invention relates to a dielectric composition, a multilayer ceramic capacitor using the same, and a method for manufacturing a multilayer ceramic capacitor.
2. Description of the Related Art
Currently, dielectrics of high capacity base metal electrode (BME) MLCCs such as X5R, X7R, X8R, and Y5V are based on sintered materials obtained by additionally adding various accessory components to a BaTiO3 base or a base modified by partially employing Ca or Zr.
These accessory component additive elements have functions such as suppression of grain growth, implementation of non-reducibility, and adjustment of dielectric characteristics to implement normal capacity and insulation characteristics of the MLCC.
Among these additive accessory components, Mg and Al, which are fixed-valence acceptors, and rare-earth elements account for the largest proportion. In addition, a small amount of variable-valence acceptors are added, and oxides containing sintering aids for increasing sinterability are included.
In the conventional compositions, a rare-earth element and Mg which is a fixed-valence acceptor, react with BaTiO3 to form a core-shell structure, and the formation of the core-shell structure is required to implement normal MLCC characteristics.
Meanwhile, with the development of the high capacity MLCC, studies have been conducted to gradually reduce the thickness of the dielectric. In this case, implementation of reliability and high temperature withstand voltage characteristics has emerged as the important issue. One of the methods to overcome this problem is a method of achieving the same capacity by applying a thicker dielectric through an increase in dielectric constant of the dielectric.